Philosophical technical vocabulary consists of two layers: purely technical terms and everyday language words used in the function of philosophical terms. Purely technical terms are comprhended as the terms pertaining to the language of science and obtaining a special meaning in philosophy and terms coined by individual philosophers to convey the nuances of their theory. The language of philosophy does not comprise exclusively formidable technical vocabulary; its terminology also includes ordinary language words used in a specific meaning. Natural living languages are characterised by vagueness and indeterminancy of the words. This linguistic feature becomes more vivid when contrasting the two language sytems, English and Latvian, and it may cause cognitive problems in translation.